Filter or strainer



Oct. 30, 193

FILTER OR STRAINER vFiled Dec. 28, 1931 A. HOARE 2 Sheets-Sheet l Home E,

Oct. 30, 1934. A. HOARE FILTER OR STRAINER 12 Sheets-Sheet 2 Filed Deo. 28, 1951 A7. Hoi/z5, ff@ @www //z/ Patented Oct. 30, 1934 iiNiTED STATES PATENT OFFICE FILTER OR STRAINER Britain Application December 28, 1931, Serial No. 583,533 In Great Britain December 31, 1930 12 Claims.

This invention relates to lters or strainers and has for its object to providean improved ilter of the kind comprising a straining wall provided with one or more slots through which the liquid 5,;is strained, a scraper blade permanently in engagement with each slot and means for causing relative movement between each blade and its slot so that the blade can be moved backwards and forwards along the slot for the purpose of 'j cleaning the slot.

In a iilter or strainer of the above kind according to the present invention not only is each slot formed or arranged with one or both ends open but the edge of the scraper blade as the 15,;1atter makes its cleaning movement relatively to the slot can emerge through the open end ofthe slot whereby foreign matter can be ejected by the blade from the open end of the slot, while further movement of the blade out of the end of 2Qgthe slot after its edge has emerged therefrom is prevented. In this way the ejection of foreign matter removed from within the slotby the blade is ensured while on the return travel of the blade any foreign matter which may cling to the edge 2530i the blade tends to be removed as this edge reenters the slot.

The form of the straining wall and the arrangement of the slot or slots therein may vary, but in one convenient arrangement a part cylindrical straining wall is provided with one or more circumferential straining slots through which the liquid to be strained flows radially, the straining wall having a part cut away so as to break the continuity of each slot in the circumferential direction and provide each slot with an open end, means being provided for preventing the radial iiow of liquid through the cut-away part or parts of each slot. A scraper blade is in continuous engagement with each slot and means are prof vided for producing relative oscillating movement between the scraper blade or blades and the straining wall about the axis of the latter, so that the scraper blades travel along the slots and,

towards the end or their travel, the leading edgev of each scrapen blade emerges through the open end of its slot so as to eject the foreign matter removed from the slot by the blade, the extent to which the edges-of the blades can emerge from the slots being limited by a stop.

In an alternative arrangement a straining wall may be substantially fiat and may have a series of substantially straight straining slots provided with open ends and a scraper blade in continuous engagement with each slot, means being provided `for reciprocating the blades within the slots for (Cl. B10-167) cleaning purposes so that the leading edges of the blades emerge through the open ends of the slots towards the end of their cleaning movement in either direction and are then prevented by a stop from further movement in such direction. In such an arrangement two substantially parallel flat straining walls may be provided, each having a series of straining slots, a support for a series of scraper blades engaging the slots being disposed and movable between these parallel straining walls.

In any case the movement of the blades relatively to the slots may be effected either manually or hydraulically.

The invention may be carried into practice in various ways but three alternative constructions according to this invention are illustrated by way of example in the accompanying drawings, in which Figure 1 is a sectional side elevation of one construction of nlter according to this invention, in which `the cleaning movement of the blades is effected manually,

Figure 2 is a sectional side elevation of a modilied construction in which the cleaning movement of the blades is effected hydraulically.

Figure 3 is a similar view to Figure 1 of an alternative construction of lter according to this invention,

Figure 4 is a section on the line 4-4 of Figure 85 3, and

Figure 5 is a plan of the straining walls and cleaning blades of the construction shown in Figures 3 and 4 with the cleaning blades at the ends of the slots.

In the construction shown in Figure 1 the filter comprises a casing A having an inlet opening A1 and an outlet opening A2. The inlet opening A1 communicates with the lower end of a chamber B of substantially rectangular crosssection the upper end of which is closed by a Wall Bl forming part of or rigidly connected to the casing A. Two parallel opposite sides of the chamber B are closed in by solid walls which may be formed integral with the part B1, while each of the other two parallel opposite side walls is constituted by a series or pack of plates B2, adjacent plates being spaced apart by distance pieces so asto provide between the plates iltering slots of the desired width. As shown the plates B2 are provided with lugs B3 through which pass bolts B4 for clamping the plates and the distance pieces together, the bolts B4 which pass through the lugs at the upper and lower ends of the plates B2 serving also to connect these plates wall of the casing A and through an opening in the part B1, is a spindle C1 the lower end of which is mounted in a bearing C2 in the lower wall of the casing A. The part of this spindle lying between the two packs of plates B2 is screwthreaded as shown at C3 and engages a screwthreaded bore in a member D to which are rigidly connected two sets of scraper blades D1 so constructed and arranged as to lie in and pass completely through the slots between adjacent plates B2 in each of the packs of plates.

It will be seen that by rotating the spindle C1 the member D can be caused to travel along the spindle so that the scraper blades D1 traverse thev ltering slots between the plates B2, and the arrangement is such that towards the end of the travel of the member D along the spindle C1 in either direction, the leading edges only of the scraper blades D1 will emerge through the open ends of the straining slots between the plates B2 as indicated in chain line at D2 and D3 so as to eject foreign matter from the ends of the slots. In this way foreign matter which is arrested between the plates is carried by the blades to the ends of the slots and then ejected.

In order to enable the spindle C1 tobe rotated, this spindle carries at its upper end a hand wheel C1. Means are also provided for indicating to an operator the position of the blades D1 in the slots, such indicating means compris- `ing a pointer member E mounted upon a screwthreaded part C5 of the spindle C1 and engaging a slot in a part E1 mounted upon the upper wall ot the casing A. It will be seen that as the hand wheel C1 is rotated the member E will be caused to travel along the slot in the part E1 as the blades D1 travel along the filtering slots, so that the position of the member E in the slot in the part E1 will give an indication of the position of the blades D1 in the filtering slots.

In the alternative construction somewhat diagrammatically illustrated in Figure 2, the general arrangement is similar to that illustrated in Figure 1, the lter proper comprising a pack or series of plates F having slots between them through which` extend blades (not shown) mounted on a blade carrier F1. In this construction the blade carrier, instead of being caused to travel longitudinally by the manual rotation of a screwthreaded shaft as in the construction shown in Figure 1, is directly connected to one end or a piston rod G which passes through glands G1 in one end of the casing H of the filter and carries at its other end a piston G2 arranged within a cylinder G3. Communicating 'respectively with the opposite ends of the cylinder G3 are passages G4, G5 through which fluid can be admitted under pressure or allowed to escape. It will be seen that by permitting the Aescape of fluid through one or other of the passages G4, G5 and delivering fluid under pressure to the other passage, movement of the piston G2'in either direction to cause corresponding movement of the cleaning blades along the slots between theY plates of the pack F can be effected.

In the alternative construction illustrated in Figures 3, 4 and 5 the lter comprises a casing J having an inlet opening J1 and an outlet opening J2. Rotatably mounted within the casing J is a substantially cylindrical straining wall built up from a series ofsuperimposed discs or plates K having distance pieces between them so as to form between the circumferential parts of adjacent plates filtering slots of the desired dimensions. Each plate or disc has four radial arms K1 which connect the peripheral part of the plate to a boss K2 through which passes a squared shaft or spindle K3. The plates and distance pieces are clamped together by four bolts K4 passing through the radial arms K1. Each of the plates has parts of its circumferential portion cut away as indicated at K5 so that two arcuate filtering slots are provided between each adjacent pair of plates, these filtering slots opening at their ends into the gap formed by the cut-away portions. Radial flow of iluid through the cut-away portions is prevented by tvvo arcuate platelike members L, while ilow of fluid into the lower end of the space enclosed by the ltering wall is prevented by an end plate. The squared spindle K3 passes freely through a boss M of a disc or cover plate M1 closing an aperture in the upper wall of the outlet passage J2 and is provided at its upper end with a handle M1 whereby the complete pack of plates con'- stituting the ltering wall can be oscillated. Formed integral with the boss M on the cover plate M1 is a spider M2 having an annular edge M3 closing in a liquid-tight manner an opening separating the chamber in' which lies the filter proper from the outlet passage J2. This annular portion M3 forms a support for one end of each of two pins or studs N on each of which is mounted a series of scraper blades N1 projecting into the filtering slots formed between the circumferential portions of adjacent plates K, the pins N being squared as shown'so as to prevent angular movement of the scraper blades relatively thereto. Adjacent scraper blades are separated by distance pieces of substantially the same thickness as the plates K, and these blades and the distance pieces are clamped together on the pins N. The lower ends of the pins N pass through holes in a disc-like member O having a central boss .O1 within which is located the lower end of the spindle K3, the boss O1 and the lower ends of the pins N engaging suitable apertures or sockets in a supporting disc P rigidly connected to the lower end of the casing J.

It will be seen that liquid entering through the inlet opening J1 must pass through the filtering slots between the circumferential portions of adjacent'plates K before it can flow through the outlet openingJ2. Further, by rocking the spindle K3 by means of the handle M4 the complete pack of filtering plates can be oscillated so as to cause the scraper blades N1 to traverse the filtering slots, the arrangement being such that the edges of these scraper blades can emerge through the open ends of the slots as indicated in Figure 5. In order to prevent the scraper blades emerging completely from the slots the members L conveniently carry stops L1 which operate as indicated in Figure 5 to limit the movement of the pack of plates K relatively to the scraper blades N1.

In either of the constructions described above it will be seen that there is little tendency for fluid to flow through the open ends of the slots so that foreign matter ejected from the ends of ythe slots tends to the slots.

What I -claim as my invention and desire vto secure by Letters Patent is:-

l. A liquid strainer including in combination inlet and outlet passages for the liquid, a straining wall having at least one open-ended straining slot through which the liquid can pass from one passage to the other, a scraper blade permanently in engagement with each slot, means for moving each blade along its slot until the leading edge only of the blade emerges from the slot, and means for preventing further movement of the blade outof the open end of the slot after the edge of the blade has thus emerged.

` I2. .A liquid strainer including in combination inlet and outlet passages for the liquid, a strain'- ing wall having at least one straining slot open at both ends through which slot the liquid can pass from one passage to the other, a scraper blade permanently in engagement with each slot, means for moving each blade to and fro along the length of its slot, the leading edge only of the blade emerging from the open end. of the slot at the end of its movement in each direction, and means for preventing further movement of the blade out of the end of the slot after the edge of the scraper blade has thus emerged.

3. A liquid strainer including in combination inlet and outlet passages for the liquid, a cylinsettle rather thanto re-enter v drical straining wall having at least one circumferential straining slot therein through which the liquid can pass radially from one passage to the other, such slot being open at both ends, a scraper blade permanently in engagement with each slot, means for moving each blade to and fro along the length of its slot, the leading edge only of the scraper blade emerging from the open end of the slot at the end of its movement in each direction, and means for preventing further movement of the blade out of the end of the slot after the edge of the scraper blade has thus emerged.

4. A liquid strainer including in combination inlet and outlet passages for the liquid, a cylindrical straining wall having at least one circumferential straining slot through which the liquid can pass radially from one passage to the other, the straining wall having a part cut away so as to break the continuity of each slot in the circumferential direction and provide each slot with open ends, a scraper blade permanently in engagement with each slot, means for moving each blade to and fro along its slot, the leading edge only of the scraper blade emerging from the open end of the slot at the end of its movement in each direction, and means for preventing further movement of the blade out of the end of the slot after the edge of the scraper blade has thus emerged.

5. A liquid strainer including in combination inlet and outlet passages for the liquid, a cylindrical straining wall having at least one circumferential straining slot through which the liquid can pass radially from one passage to the other,

`said wall having a part cut away so as to break the continuity of the slot in the circumferential direction and provide each slot with open ends, means for preventing radial ow of the liquid through the cut away part, a scraper blade permanently in engagement with each slot, means for moving each blade to and fro along its slot,

the leading edge only of the scraper blade emerging from the open end of the slot at the end of its movement in each direction, and means for preventing further movement of the blade out of the end of the slot after the edge of the scraper blade has thus emerged.

6. A liquid strainer including in combination inlet and outlet passages' for the liquid, two substantially parallel flat straining walls each having at least one straight open-ended straining slot therein through which slot the liquid can pass from one passage to the other, a scraper blade permanently in engagement with each slot, means for moving each blade along its slot until the edge of the blade emerges from the open end of the slot, and means for preventing further movement of the blade out of the end of the slot after the edge of the blade has thus emerged.

7. A liquid strainer including in combination inlet and outlet passages for the liquid, two substantially parallel flat straining walls each having at least one straight straining slot through which the liquid can pass from one passage to the other such slot being open at both ends, a scraper blade permanently in engagement with each slot, means for moving each blade to and fro along its slot the edge of the blade emerging from the open end or the slot at the end of its movement in each direction, and means for preventing further movement of the blade out of the end of the slot after the edge of the blade has thus emerged.

8. A liquid strainer including in combination inlet and outlet passages for the liquid, a cylindrical straining wall having a plurality of circiunferential straining slots therein through which the liquid can flow radially from one passage to the other, said wall being cut away to break the continuity of each slot in the circumferential direction and provide each slot with open ends, means for preventing the radial flow of liquid through the cut-away part, a series of scraper blades one of which is permanently in engagement with each slot, a common supporting member for the blades such member being disposed and movable within the straining wall whereby relative oscillating movement between the scraper blades and the straining wall can be produced about the axis of the wall to cause the scraper blades to travel along the slots, the leading edge only of each scraper blade emerging from the open end of its slot at the end of the movement in each direction, and means for preventing further movement of the blades out of the ends of the slots after the edge of each scraper blade has thus emerged.

9. A liquid strainer including in combination inlet and outlet passages for the liquid, two substantially parallel at straining walls each having a plurality of straight straining slots therein through which the liquid can pass from one passage to the other, such slots having open ends, a plurality of scraper blades one permanently in engagement with each slot, a common supporting member for the blades disposed and movable between the two parallel straining walls whereby relative oscillating movement between the scraper blades and the straining walls can be produced to cause the scraper blades to travel along the slots until the edge of each blade emerges from its slot, and means for preventing further movement of the blades out of the open ends of the slots after the edge of each blade has thus emerged.

10. A liquid strainer including in combination 'i inlet and outlet passages for the liquid, two substantially parallel iiat straining walls each having a plurality of straight straining slots therein through which the liquid can pass from one passage to the other, such slots having open ends, a plurality of scraper blades one permanently in engagement with each slot, an internally screwthreaded bossv carrying the blades, a screwthreaded shaft engaging the threaded boss and disposed betweenvthe parallel straining Walls, means for rotating the shaft to cause the blades to be moved simultaneously along the slots the edge of each blade emerging from the open end of the slot at the end of its movement, and means for preventing movement of the blades out of the open ends of the slots after the edge of each blade has thus emerged.

l1. A liquid strainer including in combination inlet and outlet passages for the liquid, two substantially parallel ilat straining walls each having a series of straight straining slots therein through which the liquid can pass from one passage to the other, such slots having open ends, a, series of scraper blades one permanently in engagement with each slot, a common supporting rod connected at one end to the blades, a piston connected to the other end of the rod, a

cylinder within which thepiston can 'be caused to reciprocate by fluid pressure and thusmove the blades simultaneously along the slots Vto clean the slots the edge ofl each blade emerging from the open end of the slot at the end of the movement of the piston,l and means for preventing further movement of the blades out of the open ends of the slots after the edge of each blade has thus emerged.

12. A liquid strainer including in combination inlet and outlet passages for the liquid, a straining wall having at least one open-ended straining slot through which the liquid can pass from one passage to the other, a scraper blade permanently in engagement with each slot, means comprising a fluid-operated piston for moving each. blade along its slot until the edge of the blade emerges from the open end of the slot and means 'for preventing further movement of the blade yout of the open end of the slot after the edge of the blade has thus emerged.

' ARTHUR I-IOARE. 

